This invention relates to a fluid motor metering device with significant improvements in accuracy and flow range spread and also a reduction in physical size. Particularly, it relates to an inexpensive, self-powered, portable, self-priming, positive displacement pump. This pump has a multiplicity of uses in the lawn and garden industry, food processing, farming and in general use wherever a metering pumping device is required.
More particularly, this pumping device has specific application to the "do-it-yourself" user as an attachment to garden hose-sprayers for the application of fertilizers, herbicides and pesticides. The use of the garden hose-sprayers with this pumping device is unexpectedly effective and accurate regardless of the water flow pressure through the hose or lack of same.
It has been known in the prior art to use Venturi devices to accomplish similar ends but they are limited by back pressure exhibited at the orifice of the Venturi. Back pressure in the Venturi system is caused, among other things, by the length of hose, its size, and the type of nozzle or sprinkler.
Professional, industrial and commercial users have available a number of positive displacement devices. However most use a valve actuation mechanism like that of a traditional light switch. That is an over-center mechanism which actuates whenever the trigger is over center. These mechanisms are located about the devices centerline but never on it due to their physical construction needs. They are mechanically linked and must travel a specified distance to be actuated.
I have unexpectedly found that by using the input flow of water into this device that it will pump another substance or substances at the rate proportional to the input fluid flow.